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        1 2     

  Subjects -> VETERINARY SCIENCE (Total: 174 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access  
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 5)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 5)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 9)
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 7)
American Journal of Primatology     Hybrid Journal   (Followers: 5)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 14)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 185)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 4)
Animals     Open Access   (Followers: 5)
Annales UMCS, Medicina Veterinaria     Open Access  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 5)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 3)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 3)
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 1)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 3)
Avian Diseases Digest     Full-text available via subscription   (Followers: 2)
Avian Pathology     Hybrid Journal   (Followers: 1)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access  
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 5)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 4)
Case Reports in Veterinary Medicine     Open Access   (Followers: 3)
Ciência Rural     Open Access   (Followers: 2)
Companion Animal     Full-text available via subscription   (Followers: 4)
Continental Journal of Animal and Veterinary Research     Open Access   (Followers: 3)
Continental Journal of Veterinary Sciences     Open Access   (Followers: 3)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 3)
Equine Health     Full-text available via subscription  
Equine Veterinary Education     Hybrid Journal   (Followers: 7)
Equine Veterinary Journal     Hybrid Journal   (Followers: 9)
Ethiopian Veterinary Journal     Open Access   (Followers: 2)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 5)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 4)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 1)
InVet     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
ISRN Veterinary Science     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 4)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 4)
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 2)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 8)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 3)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 20)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 1)
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 4)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 9)
Journal of Veterinary Internal Medicine     Hybrid Journal   (Followers: 11)
Journal of Veterinary Medical Education     Partially Free   (Followers: 8)
Journal of Veterinary Medicine     Open Access   (Followers: 2)
Journal of Veterinary Medicine and Animal Health     Open Access  
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Full-text available via subscription  
Journal of Zoo and Aquarium Research     Open Access  
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 2)
Kenya Veterinarian     Full-text available via subscription   (Followers: 1)
kleintier konkret     Hybrid Journal  
Livestock     Full-text available via subscription  
Macedonian Veterinary Review     Open Access   (Followers: 3)
MEDIA PETERNAKAN - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 2)
Medical Mycology Case Reports     Open Access  
Microbes and Health     Open Access   (Followers: 2)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 7)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 2)
Nigerian Veterinary Journal     Open Access  

        1 2     

Journal Cover Veterinary Microbiology
   [10 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
     Published by Elsevier Homepage  [2563 journals]   [SJR: 1.221]   [H-I: 75]
  • Functional metagenomic analysis reveals rivers are a reservoir for diverse
           antibiotic resistance genes
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): G.C.A. Amos , L. Zhang , P.M. Hawkey , W.H. Gaze , E.M. Wellington
      The environment harbours a significant diversity of uncultured bacteria and a potential source of novel and extant resistance genes which may recombine with clinically important bacteria disseminated into environmental reservoirs. There is evidence that pollution can select for resistance due to the aggregation of adaptive genes on mobile elements. The aim of this study was to establish the impact of waste water treatment plant (WWTP) effluent disposal to a river by using culture independent methods to study diversity of resistance genes downstream of the WWTP in comparison to upstream. Metagenomic libraries were constructed in Escherichia coli and screened for phenotypic resistance to amikacin, gentamicin, neomycin, ampicillin and ciprofloxacin. Resistance genes were identified by using transposon mutagenesis. A significant increase downstream of the WWTP was observed in the number of phenotypic resistant clones recovered in metagenomic libraries. Common β-lactamases such as bla TEM were recovered as well as a diverse range of acetyltransferases and unusual transporter genes, with evidence for newly emerging resistance mechanisms. The similarities of the predicted proteins to known sequences suggested origins of genes from a very diverse range of bacteria. The study suggests that waste water disposal increases the reservoir of resistance mechanisms in the environment either by addition of resistance genes or by input of agents selective for resistant phenotypes.


      PubDate: 2014-06-10T14:37:23Z
       
  • Prevalence and characteristics of ESBL-producing E. coli in Dutch
           recreational waters influenced by wastewater treatment plants
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Hetty Blaak , Patrick de Kruijf , Raditijo A. Hamidjaja , Angela H.A.M. van Hoek , Ana Maria de Roda Husman , Franciska M. Schets
      Outside health care settings, people may acquire ESBL-producing bacteria through different exposure routes, including contact with human or animal carriers or consumption of contaminated food. However, contact with faecally contaminated surface water may also represent a possible exposure route. The current study investigated the prevalence and characteristics of ESBL-producing Escherichia coli in four Dutch recreational waters and the possible role of nearby waste water treatment plants (WWTP) as contamination source. Isolates from recreational waters were compared with isolates from WWTP effluents, from surface water upstream of the WWTPs, at WWTP discharge points, and in connecting water bodies not influenced by the studied WWTPs. ESBL-producing E. coli were detected in all four recreational waters, with an average concentration of 1.3 colony forming units/100ml, and in 62% of all samples. In surface waters not influenced by the studied WWTPs, ESBL-producing E. coli were detected in similar concentrations, indicating the existence of additional ESBL-E. coli contamination sources. Isolates with identical ESBL-genes, phylogenetic background, antibiotic resistance profiles, and sequence type, were obtained from effluent and different surface water sites in the same watershed, on the same day; occasionally this included isolates from recreational waters. Recreational waters were identified as a potential exposure source of ESBL-producing E. coli. WWTPs were shown to contribute to the presence of these bacteria in surface waters, but other (yet unidentified) sources likely co-contribute.


      PubDate: 2014-06-10T14:37:23Z
       
  • Pharmacokinetic–pharmacodynamic (PK–PD) modeling and the
           rational selection of dosage regimes for the prudent use of antimicrobial
           drugs
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Mark G. Papich
      One of the strategies to decrease inappropriate antimicrobial use in veterinary medicine is to apply pharmacokinetic–pharmacodynamic (PK–PD) principles to dosing regimens. If antimicrobials are used appropriately by applying these principles to attain targets for area-under-the-curve to MIC ratio (AUC/MIC), peak concentration to MIC ratio (CMAX/MIC), and time above MIC (T>MIC), more effective antibiotic therapy is possible, thus avoiding ineffective administration. Another mechanism whereby inappropriate antibiotic administration can be avoided is to use accurate Interpretive Criteria established by the Clinical Laboratory Standards Institute (CLSI) for breakpoint selection. Inaccurate breakpoints will encourage antibiotic administration that is likely to be ineffective. For newly approved antimicrobials, three criteria are used for determining breakpoints: PK–PD criteria, MIC distributions, and clinical response. For older (often generic drugs) evaluated by the CLSI, recent clinical data may not be available and breakpoints are derived from PK–PD principles, wild-type distributions, and Monte Carlo simulations. It is the goal of the CLSI subcommittee that these revised breakpoints will encourage more effective antimicrobial use and avoid unnecessary antimicrobial administration.


      PubDate: 2014-06-10T14:37:23Z
       
  • A cocktail of in vitro efficient phages is not a guarantee for in vivo
           therapeutic results against avian colibacillosis
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Jessica Tsonos , Leon H. Oosterik , Huruma N. Tuntufye , Jochen Klumpp , Patrick Butaye , Henri De Greve , Jean-Pierre Hernalsteens , Rob Lavigne , Bruno M. Goddeeris
      Avian pathogenic Escherichia coli (APEC) causes colibacillosis in poultry, leading to important economic losses worldwide. To cure APEC-infected chickens, a cocktail of four different APEC-specific bacteriophages (phages) was composed and tested. Specific phages were selected from a collection of phages isolated in Belgium. The selection was based on their obligate lytic infection cycle, a broad host range, low cross-resistance and low frequency of development of resistant APEC mutants. Genome analysis of the phages indicated they were close relatives of T4 and N4, considered to be safe in vivo. Chickens were intratracheally infected with APEC strain CH2 (serogroup O78), causing a mortality of about 50% during the seven days following the infection. The phage cocktail was administered 2h after the infection, via three different ways: intratracheally, intra-esophageally or via the drinking water. Treated groups did not show a significant decrease in mortality, lesion scores or weight loss compared to untreated groups, although the APEC-specific phages could be re-isolated from the lung and heart of chickens that were euthanized. Moreover, the re-isolated bacteria from infected chickens had remained sensitive to the phage cocktail. Our results indicate that the efficiency of the phage cocktail used in treating CH2-infected chickens in vivo is negligible, even though in vitro, the phages in the cocktail were able to efficiently lyse the APEC strain CH2. Our results emphasize that the ‘traditional’ pathway of isolation, followed by phenotypical and genotypical characterization of phages composing the cocktail, does not lead to success in phage therapy in all cases.


      PubDate: 2014-06-10T14:37:23Z
       
  • Hurdles in bacteriophage therapy: Deconstructing the parameters
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Jessica Tsonos , Dieter Vandenheuvel , Yves Briers , Henri De Greve , Jean-Pierre Hernalsteens , Rob Lavigne
      Bacterial infections in animals impact our food production, leading to economic losses due to food rejection and the need for preventive and curative measures. Since the onset of the antibiotic era, the rise of antibiotic-resistant pathogens is causing scares in health care and food producing facilities worldwide. In the search of new therapeutics, re-evaluation of bacteriophage (phage) therapy, using naturally occurring bacterial viruses to tackle infections, is gaining interest. Many studies report about phage therapy success, showing the value and power of these natural viruses. Although phages carry some interesting traits and their basic biology is now well understood, this review argues that phage therapy has not revealed all of its secrets and many parameters remain understudied, making the outcome of phage therapy highly variable depending on the disease incidence. These difficulties include poorly understood mechanisms of phage penetration and distribution throughout the body, the variable expression and accessibility of phage receptors on the bacterial host in in vivo conditions and the unusual (non-linear) phage pharmacokinetics. These parameters are not easily measured in realistic in vivo settings, but are nevertheless important hurdles to overcome the high variability of phage therapy trials. This critical approach is in accordance with Goethe's statement; “Difficulties increase the nearer we get to the goal”. However, since the importance of the goal itself also rises, both difficulties and goal justify the need for additional in depth research in this domain.


      PubDate: 2014-06-10T14:37:23Z
       
  • Enterobacter cloacae with a novel variant of ACT AmpC beta-lactamase
           originating from glaucous gull (Larus hyperboreus) in Svalbard
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Ivan Literak , Ivan Manga , Katarzyna Wojczulanis-Jakubas , Magdalena Chroma , Ivana Jamborova , Hana Dobiasova , Miroslava Htoutou Sedlakova , Alois Cizek
      We aimed at Escherichia coli and Enterobacter cloacae isolates resistant to cephalosporins and fluoroquinolones and Salmonella isolates in wild birds in Arctic Svalbard, Norway. Cloacal swabs of little auks (Alle alle, n =215) and samples of faeces of glaucous gulls (Larus hyperboreus, n =15) were examined. Inducible production of AmpC enzyme was detected in E. cloacae KW218 isolate. Sequence analysis of the 1146bp PCR product of the ampC gene from this isolate revealed 99% sequence homology with the bla ACT-14 and bla ACT-5 AmpC beta-lactamase genes. Four, respectively six of the identified single nucleotide polymorphisms generated amino acid substitutions in the amino acid chain. As the ampC sequence polymorphism in the investigated E. cloacae strain was identified as unique, we revealed a novel variant of the ampC beta-lactamase gene bla ACT-23.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial resistance determinants in Staphylococcus spp. recovered
           from birds of prey in Portugal
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Margarida Sousa , Nuno Silva , Gilberto Igrejas , Filipe Silva , Roberto Sargo , Nuno Alegria , Daniel Benito , Paula Gómez , Carmen Lozano , Elena Gómez-Sanz , Carmen Torres , Manuela Caniça , Patrícia Poeta
      Antibiotic resistance among wild animals represent an emerging public health concern. The objective of this study was to analyze the staphylococcal nasal microbiota in birds of prey and their content in antimicrobial resistance determinants. Nasal samples from 16 birds of prey were collected, swabs were dipped and incubated into BHI broth [6.5% NaCl] and later seeded on manitol salt agar and oxacillin-resistance screening agar base media. Staphylococcal colonies were isolated from both media and were identified by biochemical and molecular methods. Susceptibility testing to 18 antimicrobial agents was performed by disk-diffusion method. Six of the 16 tested animals carried staphylococci (37.5%) and 7 isolates of the following species were recovered: Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus sciuri rodentium, Staphylococcus cohnii urealitycum, and Staphylococcus gallinarum. The S. aureus isolate was penicillin-resistant (with blaZ gene) but methicillin-susceptible and was ascribed to spa-type t012, sequence-type ST30 and agr-type III. The S. epidermidis isolate carried blaZ, mecA, mrs(A/B), mphC, tet(K), drfA, and fusC genes, ica operon, and was typed as ST35. The genes ant6′-Ia, tet(K), tet(L), dfrG, cat 221, cat 194, and cat 223 were detected in S. saprophyticus or S. gallinarum isolates. Birds of prey seem to be a natural reservoir of S. aureus and coagulase-negative staphylococci resistant to multiple antibiotics. Due to the convergence between habitats, the contact between wildlife, other animals and humans is now more common and this involves an increased possibility of interchange of these microorganisms in the different ecosystems.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial-resistant Enterobacteriaceae from humans and wildlife in
           Dzanga-Sangha Protected Area, Central African Republic
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Martina Janatova , Katerina Albrechtova , Klara Judita Petrzelkova , Monika Dolejska , Ivo Papousek , Martina Masarikova , Alois Cizek , Anguelique Todd , Kathryn Shutt , Bara Kalousova , Ilona Profousova-Psenkova , David Modry , Ivan Literak
      Antimicrobial resistance is a worldwide concern of public health. Unfortunately, resistant bacteria are spreading to all ecosystems, including the strictly protected ones. We investigated antimicrobial resistance in gastrointestinal Enterobacteriaceae of wild mammals and people living within Dzangha-Sangha Protected Areas, Central African Republic, with an emphasis on extended-spectrum β-lactamase (ESBL) and plasmid-mediated quinolone resistance (PMQR) genes. We compare resistance genes found in microbiota of humans, gorillas habituated and unhabituated to humans and other wildlife. In gorillas, we additionally investigate the presence of ESBL resistant isolates after treatment by ceftiofur. We found a considerable prevalence of multiresistant Enterobacteriaceae isolates with ESBL and PMQR genes in humans (10% and 31%, respectively). Among wildlife the most significant findings were CTX-M-15-producing Klebsiella pneumoniae in a habituated gorilla and a multiresistant Escherichia coli isolate with gene qepA in an unhabituated gorilla. Other isolates from wildlife were mostly represented by qnrB-harboring Citrobacter spp. The relatedness of resistant E. coli was investigated in a PFGE-based dendrogram; isolates from gorillas showed less than 80% similarity to each other and less than 80% similarity to human isolates. No ESBL-producing isolates were found in animals treated by ceftiofur. Although we did not detect any bacterial clone common to wildlife and humans, we detected an intersection in the spectrum of resistance genes found in humans and gorillas, represented by bla CTX-M-15 and qepA.


      PubDate: 2014-06-10T14:37:23Z
       
  • An emerging public health problem: Acquired carbapenemase-producing
           microorganisms are present in food-producing animals, their environment,
           companion animals and wild birds
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Beatriz Guerra , Jennie Fischer , Reiner Helmuth
      Worldwide, the emergence and global spread of microorganisms with acquired carbapenemases is of great concern. The reservoirs for such organisms are increasing, not only in hospitals, but also in the community and environment. A new and important development is the presence of such organisms in livestock, companion animals and wildlife. During the last three years, carbapenemase-producing Escherichia coli, Salmonella spp. (VIM-1 producers) and Acinetobacter spp. (producing OXA-23 and NDM-1) in livestock animals (poultry, cattle and swine) and their environment have been reported. In addition, the isolation of NDM-1-producing E. coli, OXA-48 in E. coli and Klebsiella pneumoniae or OXA-23 in Acinetobacter spp. from companion animals (cats, dogs or horses) has also been observed. Other reports have described the presence of NDM-1-producing Salmonella isolated from wild birds, as well as OXA-23-like-producing Acinetobacter baumannii in ectoparasites. However, until now carbapenemase producers from foods have not been detected. For humans in contrast carbapenem-producing Salmonella isolates are increasingly reported. The real prevalence of carbapenemase-encoding genes in zoonotic bacteria or commensals from animals is unknown. Consequently, there is a need for intensified surveillance on the occurrence of carbapenemase-producing bacteria in the food chain and other animal sources in order to assist in the formulation of measures to prevent their potential spread.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial susceptibility of Salmonella isolates from healthy pigs and
           chickens (2008–2011)
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Anno de Jong , Annemieke Smet , Carolin Ludwig , Bernd Stephan , Evelyne De Graef , Mia Vanrobaeys , Freddy Haesebrouck
      Using the agar dilution method, antimicrobial susceptibility to human-use antibiotics was determined among Belgian faecal Salmonella isolates from healthy pigs and broiler chickens. Both epidemiological cut-off values and clinical breakpoints were applied for interpretation of the results. Cephalosporin-resistant isolates were examined for the presence of genes encoding CTX-M, SHV, TEM and CMY β-lactamases. All isolates with decreased quinolone susceptibility were screened for plasmid-borne genes qnr, qepA and aac(6′)-Ib-cr. In all, 368 Salmonella isolates were recovered from pigs and 452 from chickens. Clinical resistance to ciprofloxacin was absent in isolates of both host species, and was 1.9 and 13.1% to cefotaxime in pig and poultry isolates, respectively. Decreased susceptibility to cefotaxime amounted to 2.2 and 0.7%, whereas for ciprofloxacin this was 3.0 and 23.0% in pig and poultry isolates, respectively. Ciprofloxacin decreased susceptibility was limited to few serovars, mainly Paratyphi B. Multidrug resistance was markedly higher for pig isolates (39.7%) than for chicken isolates (17.3%). Sixty-six cefotaxime-resistant isolates, 59 from chickens and 7 from pigs, were phenotypically determined as ESBL/AmpC producers; predominantly Paratyphi B and Typhimurium serovars. Bla CTX-M (mostly bla CTXM-1, but also bla CTXM-2 and bla CTXM-9) and bla TEM-52 were the predominant ESBL genes. Only few isolates expressed SHV-12 or an AmpC enzyme (CMY-2). Isolates of four serovars carried qnr genes: Brandenburg and Llandof from pigs, both qnrS; Indiana and Paratyphi B from chickens with qnrB and qnrA. The latter isolate carried bla CTX-M-9 and was the only strain with a plasmid-borne quinolone resistance gene among the ESBL/AmpC producers. This Salmonella survey confirms that the ESBL/AmpC producers are particularly prevalent in chickens (12.8%), and much less in pigs (1.9%). A link between plasmid-borne quinolone resistance genes and ESBLs/AmpC was uncommon.


      PubDate: 2014-06-10T14:37:23Z
       
  • Ornamental fish as a source of plasmid-mediated quinolone resistance genes
           and antibiotic resistance plasmids
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Hana Dobiasova , Iva Kutilova , Veronika Piackova , Tomas Vesely , Alois Cizek , Monika Dolejska
      Growing ornamental fish industry is associated with public health concerns including extensive antibiotic use accompanied by increasing antibiotic resistance. The aim of this study was to analyze Aeromonas isolates from imported tropical ornamental fish and coldwater koi carps bred in the Czech Republic to assess the potential risk of ornamental fish as a source of plasmid-mediated quinolone resistance genes (PMQR) and antibiotic resistance plasmids. A collection of Aeromonas spp. with reduced susceptibility to ciprofloxacin (MIC≥0.05mg/L) was selected for the detection of PMQR genes. Isolates harbouring PMQR genes were further analyzed for the additional antibiotic resistance, integron content, clonality, biofilm production and transferability of PMQR genes by conjugation and transformation. Comparative analysis of plasmids carrying PMQR genes was performed. Fifteen (19%, n =80) isolates from koi carps and 18 (24%, n =76) isolates from imported ornamental fish were positive for qnrS2, aac(6′)-Ib-cr or qnrB17 genes. PMQR-positive isolates from imported ornamental fish showed higher MIC levels to quinolones, multiresistance and diverse content of antibiotic resistance genes and integrons compared to the isolates from the carps. Related IncU plasmids harbouring qnrS2 and aac(6′)-Ib-cr genes were found in Aeromonas spp. from imported ornamental fish and koi carps from various geographical areas. Ornamental fish may represent a potential source of multiresistant bacteria and mobile genetic elements for the environment and for humans.


      PubDate: 2014-06-10T14:37:23Z
       
  • Pheno- and genotypic analysis of antimicrobial resistance properties of
           Yersinia ruckeri from fish
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Yidan Huang , Geovana Brenner Michael , Roswitha Becker , Heike Kaspar , Joachim Mankertz , Stefan Schwarz , Martin Runge , Dieter Steinhagen
      Enteric red-mouth disease, caused by Yersinia ruckeri, is an important disease in rainbow trout aquaculture. Antimicrobial agents are frequently used in aquaculture, thereby causing a selective pressure on bacteria from aquatic organisms under which they may develop resistance to antimicrobial agents. In this study, the distribution of minimal inhibitory concentrations (MICs) of antimicrobial agents for 83 clinical and non-clinical epidemiologically unrelated Y. ruckeri isolates from north west Germany was determined. Antimicrobial susceptibility was conducted by broth microdilution at 22±2°C for 24, 28 and 48h. Incubation for 24h at 22±2°C appeared to be suitable for susceptibility testing of Y. ruckeri. In contrast to other antimicrobial agents tested, enrofloxacin and nalidixic acid showed a bimodal distribution of MICs, with one subpopulation showing lower MICs for enrofloxacin (0.008–0.015μg/mL) and nalidixic acid (0.25–0.5μg/mL) and another subpopulation exhibiting elevated MICs of 0.06–0.25 and 8–64μg/mL, respectively. Isolates showing elevated MICs revealed single amino acid substitutions in the quinolone resistance-determining region (QRDR) of the GyrA protein at positions 83 (Ser83-Arg or -Ile) or 87 (Asn87-Tyr), which raised the MIC values 8- to 32-fold for enrofloxacin or 32- to 128-fold for nalidixic acid. An isolate showing elevated MICs for sulfonamides and trimethoprim harbored a ∼8.9kb plasmid, which carried the genes sul2, strB and a dfrA14 gene cassette integrated into the strA gene. These observations showed that Y. ruckeri isolates were able to develop mutations that reduce their susceptibility to (fluoro)quinolones and to acquire plasmid-borne resistance genes.


      PubDate: 2014-06-10T14:37:23Z
       
  • Molecular characterization of antibiotic resistance in Pseudomonas and
           Aeromonas isolates from catfish of the Mekong Delta, Vietnam
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Hoang Nam Kha Nguyen , Thi Thu Hao Van , Huu Thinh Nguyen , Peter M. Smooker , Jeff Shimeta , Peter J. Coloe
      A collection of 116 motile Pseudomonas spp. and 92 Aeromonas spp. isolated from 15 Vietnamese intensive catfish farms was analyzed to examine the molecular antibiotic resistance characteristics and the transferability of resistance markers within and between species. High levels of resistance to ampicillin, trimethoprim/sulfamethoxazole, nalidixic acid, chloramphenicol, and nitrofurantoin were observed. The percentage of multiple drug resistance of Pseudomonas spp. and Aeromonas spp. isolates was 96.6% and 61.9%, respectively. The multiple antibiotic resistance (MAR) index mean values of 0.457 and 0.293 of Pseudomonas and Aeromonas isolates, respectively, indicated that these isolates were exposed to high risk sources of contamination where antibiotics were commonly used. Approximately 33% of Pseudomonas spp. and 28% of Aeromonas spp. isolates from catfish contained class 1 integrons, but no class 2 integrons were detected. Several common resistance genes including aadA, dfrA and catB were harbored in class 1 integrons. Large plasmids (>55kb) were frequently detected in 50% and 71.4% of the plasmids extracted from Pseudomonas and Aeromonas isolates, respectively. Conjugation and transformation experiments demonstrated the successful transfer of all or part of the resistance phenotypes of catfish isolates to the recipient strains, including laboratory strains and strains isolated from this study. These results highlight the likely role of catfish bacteria as a reservoir of antibiotic resistant, Gram-negative bacteria harboring a pool of mobile genetic elements that can readily be transferred intra- and interspecies. To our knowledge, this is the first report on molecular characterization of antibiotic resistance of bacteria isolated from catfish in Vietnam.


      PubDate: 2014-06-10T14:37:23Z
       
  • In vivo spread of macrolide-lincosamide-streptogramin B (MLSB)
           resistance—A model study in chickens
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): D. Marosevic , D. Cervinkova , H. Vlkova , P. Videnska , V. Babak , Z. Jaglic
      The influence of specific and non-specific antibiotic pressure on in vivo spread of macrolide-lincosamide-streptogramin B (MLSB) resistance was evaluated in this study. Chickens repeatedly inoculated with Enterococcus faecalis harbouring the plasmid pAMβ1 carrying the erm(B) gene were perorally treated for one week with tylosin, lincomycin (both specific antibiotic pressure) and chlortetracycline (non-specific antibiotic pressure). Antibiotic non-treated but E. faecalis inoculated chickens served as a control. To quantify the erm(B) gene and characterise intestinal microflora, faecal DNA was analysed by qPCR and 454-pyrosequencing. Under the pressure of antibiotics, a significant increase in erm(B) was observed by qPCR. However, at the final stage of the experiment, an increase in erm(B) was also observed in two out of five non-treated chickens. In chickens treated with tylosin and chlortetracycline, the increase in erm(B) was accompanied by an increase in enterococci. However, E. faecalis was at the limit of detection in all animals. This suggests that the erm(B) gene spread among the gut microbiota other than E. faecalis. Pyrosequencing results indicated that, depending on the particular antibiotic pressure, different bacteria could be responsible for the spread of MLSB resistance. Different species of MLSB-resistant enterococci and streptococci were isolated from cloacal swabs during and after the treatment. PFGE analysis of MLSB-resistant enterococci revealed four clones, all differing from the challenge strain. All of the MLSB-resistant isolates harboured a plasmid of the same size as pAMβ1. This study has shown that MLSB resistance may spread within the gut microbiota under specific and non-specific pressure and even in the absence of any antimicrobial pressure. Finally, depending on the particular antibiotic pressure, different bacterial species seems to be involved in the spread of MLSB resistance.


      PubDate: 2014-06-10T14:37:23Z
       
  • Quality control ranges for cefoperazone 30μg disks for Staphylococcus
           aureus ATCC® 25923 and Escherichia coli ATCC® 25922
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Andrea T. Feßler , John Turnidge , Stefan Schwarz
      The third generation cephalosporin cefoperazone is commonly used for bovine mastitis therapy. So far, the cefoperazone susceptibility testing using 30μg disks was hampered by the lack of quality control (QC) ranges and the respective interpretive criteria. The aim of this study was to develop CLSI-approved QC ranges for Staphylococcus aureus ATCC® 25923 and Escherichia coli ATCC® 25922. An interlaboratory trial including eight laboratories was conducted. Each laboratory tested both QC reference strains ten times using two lots of cefoperazone 30μg disks and three lots of Mueller–Hinton agar. The results were analysed by using the published statistical analysis method. Based on the data, zone diameters of 23–34mm and 24–33mm were established as QC ranges for the 30μg disk and S. aureus ATCC® 25923 and E. coli ATCC® 25922, respectively. These new QC ranges have been recently approved by the Clinical and Laboratory Standards Institute and will help diagnostic laboratories to validate their cefoperazone testing results using 30μg disks.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial resistance in bacteria from animals and the environment
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Patrick Butaye , Engeline van Duijkeren , John F. Prescott , Stefan Schwarz



      PubDate: 2014-06-10T14:37:23Z
       
  • The resistance tsunami, antimicrobial stewardship, and the golden age of
           microbiology
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): John F. Prescott
      Modern medicine is built on antibiotics. Antibiotics are something that we take for granted. We have however spent over 60 years educating bacteria to become resistant, and the global resistance tsunami has caught everyone unawares. Since bacteria have changed, we also have to change, and to change most of the practices of how we use antibiotics. Because the development of new antibiotics is so expensive, a stewardship approach may help to preserve those that we have now while we work to develop new antibiotics and to develop other approaches to controlling and treating infections. We need to adopt the ethic of Good Stewardship Practice (GSP) as an active and dynamic process of continuous improvement in antibiotic use, a process with many steps of different sizes involving everyone involved in antibiotic use. All antibiotic users have an important role to play in GSP. Although the resistance situation is pessimistic, and the future of antibiotics looks uncertain, we are fortunately entering what may be seen as the golden age of microbiology. This encompasses an astonishing array of technologies for rapid pathogen and resistance gene detection, for clone identification by genome sequencing, for identification of novel bacterial genes and for identification of the Achilles’ heels of different pathogens. Future antibiotics may have to be far more targeted to the individual pathogen and the site of infection. A global tax on antibiotics might reduce their use while funding the cost of developing new antibiotics and new approaches to control of infectious diseases.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial resistance monitoring projects for zoonotic and indicator
           bacteria of animal origin: Common aspects and differences between EASSA
           and EFSA
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Hilde Moyaert , Anno de Jong , Shabbir Simjee , Valérie Thomas
      Resistance monitoring programmes are essential to generate data for inclusion in the scientific risk assessment of the potential for transmission of antimicrobial-resistant bacteria or their resistance determinants from food-producing animals to humans. This review compares the technical specifications on monitoring of antimicrobial resistance in zoonotic Salmonella, Campylobacter and indicator Escherichia coli and Enterococcus as performed by the European Food Safety Authority (EFSA) with veterinary pharmaceutical industry's European Antimicrobial Susceptibility Surveillance in Animals (EASSA) programme. The authors conclude that most of EFSA's recent monitoring recommendations have been covered by EASSA since the start of the latter programme in 1998. The major difference between the two programmes is the classification into ‘susceptible’ versus ‘resistant’. While EFSA categorises all isolates with an MIC value above the epidemiological cut-off value as ‘resistant’, EASSA differentiates between ‘percentage decreased susceptible’ and ‘percentage clinical resistant’ strains by applying both epidemiological cut-off values and clinical breakpoints. Because there is still a need to further improve harmonisation among individual EU Member State activities, Animal Health Industry welcomes EFSA's initiative to further improve the quality of resistance monitoring as it is of utmost importance to apply standardised collection procedures and harmonised susceptibility testing, when monitoring antimicrobial resistance across Europe.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial susceptibility and distribution of inhibition zone diameters
           of bovine mastitis pathogens in Flanders, Belgium
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): K. Supré , K. Lommelen , L. De Meulemeester
      In dairy farms, antimicrobial drugs are frequently used for treatment of (sub)clinical mastitis. Determining the antimicrobial susceptibility of mastitis pathogens is needed to come to a correct use of antimicrobials. Strains of Staphylococcus aureus (n =768), Streptococcus uberis (n =939), Streptococcus dysgalactiae (n =444), Escherichia coli (n =563), and Klebsiella species (n =59) originating from routine milk samples from (sub)clinical mastitis were subjected to the disk diffusion method. Disks contained representatives of frequently used antibiotics in dairy. A limited number of clinical breakpoints were available through CLSI, and showed that susceptibility of Staph. aureus, E. coli, and Klebsiella was moderate to high. For streptococcal species however, a large variation between the tested species and the different antimicrobials was observed. In a next step, wild type populations were described based on epidemiological cut off values (EUCAST). Because of the limited number of official cut off values, the data were observed as a mastitis subpopulation and self-generated cut off values were created and a putative wild type population was suggested. The need for accurate clinical breakpoints for veterinary pathogens is high. Despite the lack of these breakpoints, however, a population study can be performed based on the distribution of inhibition zone diameters on the condition that a large number of strains is tested.


      PubDate: 2014-06-10T14:37:23Z
       
  • Two different erm(C)-carrying plasmids in the same methicillin-resistant
           Staphylococcus aureus CC398 isolate from a broiler farm
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Sarah Wendlandt , Kristina Kadlec , Andrea T. Feßler , Engeline van Duijkeren , Stefan Schwarz
      During a study on plasmid-borne antimicrobial resistance among methicillin-resistant Staphylococcus aureus (MRSA) isolates from broiler farms, an MRSA isolate was identified which carried multiple plasmids. This MRSA isolate belonged to CC398 and exhibited spa type t3015 and dru type dt11a. Plasmid profiling revealed the presence of one large and two small plasmids. The resistance genes tet(L) (tetracycline resistance), dfrK (trimethoprim resistance) and aadD (kanamycin/neomycin resistance) were located on the large plasmid. Both small plasmids, designated pSWS371 and pSWS372, carried only an erm(C) gene for macrolide/lincosamide resistance. Sequence analysis revealed that the 2458-bp plasmid pSWS371 carried only a repL gene for plasmid replication in addition to the erm(C) gene. In contrast, the 3882-bp plasmid pSWS372 harbored – in addition to the erm(C) gene – three more genes: a repF gene for plasmid replication, a cop-6 gene for a small protein potentially involved in copy number control of the plasmid and a novel pre/mob gene for a protein involved in plasmid recombination and mobilization. The erm(C) genes of both small plasmids exhibited constitutive erm(C) gene expression and analysis of the respective translational attenuators identified deletions of 16bp and 74bp which explain the constitutive expression. The simultaneous presence of two small plasmids that carry the same resistance gene in the same MRSA isolate is a rare observation. The fact that both plasmids belong to different incompatibility groups as specified by the different rep genes, repL and repF, explains why they can stably coexist in the same bacterial cell.


      PubDate: 2014-06-10T14:37:23Z
       
  • Tylosin susceptibility of staphylococci from bovine mastitis
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Monika Entorf , Andrea T. Feßler , Kristina Kadlec , Heike Kaspar , Joachim Mankertz , Thomas Peters , Stefan Schwarz
      Although the 16-membered macrolide tylosin is commonly used for the treatment of bovine mastitis, little information is currently available about the susceptibility of mastitis pathogens to tylosin. In the present study, 112 Staphylococcus aureus and 110 coagulase-negative Staphylococcus (CoNS) spp. isolates from cases of bovine mastitis were tested by broth microdilution and agar disk diffusion with 30μg tylosin disks. Susceptibility to erythromycin was tested by broth microdilution and disk diffusion using 15μg disks. Both test populations showed bimodal distributions of minimal inhibitory concentrations (MICs) and zone diameters with eleven S. aureus and eight CoNS isolates showing tylosin MICs of ≥256μg/ml and no zones of growth inhibition around the tylosin 30μg disks. All 19 isolates with tylosin MICs of ≥256μg/ml were also resistant to erythromycin. For six additional erythromycin-resistant isolates, tylosin MICs of 1–8μg/ml were observed. One S. aureus and two CoNS isolates showed inducible macrolide resistance. PCR analysis of the 25 erythromycin-resistant staphylococcal isolates identified the resistance genes erm(A), erm(B), erm(C), erm(T), mph(C) and msr(A) alone or in different combinations. An excellent correlation between the results of the different tylosin susceptibility tests (broth microdilution versus disk diffusion) was seen for S. aureus and CoNS isolates. Since tylosin does not induce the expression of the aforementioned erm genes, isolates with an inducible resistance phenotype may – if only tylosin is tested – be falsely classified as tylosin-susceptible. Thus, erythromycin should be tested in parallel and tylosin should only be used for the treatment of infections caused by erythromycin-susceptible staphylococci.


      PubDate: 2014-06-10T14:37:23Z
       
  • Prevalence of methicillin-resistant Staphylococcus aureus carrying mecA or
           mecC in dairy cattle
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): E. van Duijkeren , P.D. Hengeveld , M. Albers , G. Pluister , P. Jacobs , L. Heres , A.W. van de Giessen
      In the Netherlands, livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has been found in pigs, veal calves, horses and poultry. However, little is known about its prevalence in healthy dairy cattle. Recently, a new mec gene, called mecC, has been found in methicillin-resistant S. aureus (MRSA) isolates from humans and animals in several countries. The objective of our pilot study was to investigate the prevalence of MRSA (mecA and mecC) in dairy cows at a large slaughterhouse. Samples from the skin between the udder and hind leg were taken from 411 cows. The samples were incubated in Mueller–Hinton enrichment broth with 6.5% NaCl, followed by selective enrichment and plated onto Columbia agar with 5% sheep blood, Brilliance MRSA 2 agar and Baird–Parker agar. Suspected colonies were tested by PCR for a S. aureus specific DNA fragment, the mecA and mecC genes and the Panton-Valentine leucotoxin (PVL) genes. All MRSA isolates and methicillin-susceptible S. aureus (MSSA) isolates were typed by spa typing and MLVA typing. Sixteen of 411 (3.9%) cows, all originating from different farms, were found to be MRSA positive and this prevalence is lower than in Dutch pigs, veal calves and broilers. All MRSA isolates belonging to livestock-associated MLVA complex 398, were PVL-negative and spa type t011 predominated. MSSA isolates (n =39) were of many different MLVA types and spa type t543 was found most often. Four MSSA isolates belonging to MLVA clonal complex 398 and spa types t011 (n =2), t108 and t034 were isolated from different MRSA-negative animals. In conclusion, the prevalence of MRSA in dairy cows was low and isolates carrying the mecC gene were not found, indicating that it is absent or has a low prevalence (<0.73%) in Dutch dairy cows.


      PubDate: 2014-06-10T14:37:23Z
       
  • Molecular epidemiology of methicillin-resistant Staphylococcus sciuri in
           healthy chickens
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Stéphanie Nemeghaire , M. Angeles Argudín , Freddy Haesebrouck , Patrick Butaye
      Staphylococcus sciuri is commonly found on the skin of animals and humans as well as in the environment. However, little is known on its prevalence, resistance and epidemiology. Therefore, we investigated the prevalence of methicillin resistant S. sciuri (MRSS) strains in poultry, as they may represent a reservoir of resistance genes for other strains. In 2011, 281 poultry farms were sampled by taking nasal swabs of 20 animals. The swabs were pooled and MRSS were selectively isolated. Genus and methicillin resistance were determined by PCR and species identification was performed using transfer RNA-intergenic spacer analysis. MRSS were further characterised by SCCmec typing, PFGE, microarray and susceptibility testing. Eighty-seven MRSS were isolated resulting in an estimated prevalence of 31.0%. The prevalence in broilers did not significantly differ from that in layers. Most isolates harboured a non-typeable SCCmec and a little less than 40% carried SCCmec type III. Isolates from broiler farms carried mostly the SCCmec type III, while isolates from layer farms carried mostly the non-typeable SCCmec cassette. The 87 isolates generated 47 different SmaI-PFGE profiles that grouped in two main clusters corresponding to the two farm types. All isolates were resistant to fusidic acid, tiamulin and gentamicin and were sensitive to rifampicin and vancomycin. Isolates selected for microarray analysis carried a broad range of antimicrobial resistance and virulence genes. This study showed that MRSS is carried by healthy chickens at the same level in both broilers and layers. They represent a large reservoir for resistance and virulence genes. Strains from layers and broilers represent different clusters.


      PubDate: 2014-06-10T14:37:23Z
       
  • The ecological importance of the Staphylococcus sciuri species group as a
           reservoir for resistance and virulence genes
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Stéphanie Nemeghaire , M. Angeles Argudín , Andrea T. Feßler , Tomasz Hauschild , Stefan Schwarz , Patrick Butaye
      The Staphylococcus sciuri species group includes five species that are most often presented as commensal animal-associated bacteria. The species of this group are Staphylococcus sciuri (with three subspecies), Staphylococcus lentus, Staphylococcus vitulinus, Staphylococcus fleurettii and Staphylococcus stepanovicii. Members of these group are commonly found in a broad range of habitats including animals, humans and the environment. However, those species have been isolated also from infections, both in veterinary and human medicine. Members of this group have been shown to be pathogenic, though infections caused by these species are infrequent. Furthermore, members of the S. sciuri species group have also been found to carry multiple virulence and resistance genes. Indeed, genes implicated in biofilm formation or coding for toxins responsible of toxic shock syndrome and multi-resistance, similar to those carried by Staphylococcus aureus, were detected. This group may thereby represent a reservoir for other bacteria. Despite its recognized abundance as commensal bacteria and its possible role as reservoir of virulence and resistance genes for other staphylococci, the S. sciuri species group is often considered harmless and, as such, not as well documented as, for example, S. aureus. More investigation into the role of the S. sciuri species group as commensal and pathogenic bacteria is required to fully assess its medical and veterinary importance.


      PubDate: 2014-06-10T14:37:23Z
       
  • Antimicrobial resistance in methicillin susceptible and methicillin
           resistant Staphylococcus pseudintermedius of canine origin: Literature
           review from 1980 to 2013
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Arshnee Moodley , Peter Damborg , Søren Saxmose Nielsen
      Staphylococcus pseudintermedius is a commensal and a common opportunistic pathogen causing mainly infections of the integumentary system in dogs. The recent emergence of multidrug-resistant S. pseudintermedius isolates, in particular methicillin-resistant strains (MRSP) is a threat to small animal health and highlights the need for antimicrobial resistance surveillance to detect trends and potentially perform timeous interventions. We systematically reviewed 202 published articles to investigate temporal changes in antimicrobial resistance in clinical and commensal S. pseudintermedius isolated from dogs in 27 countries between 1980 and 2013. Resistance to the most common antimicrobials tested for in published studies and important for the treatment of staphylococcal infections in dogs were assessed separately for methicillin resistant (MRSP) and methicillin susceptible (MSSP) isolates. Stratified by MSSP and MRSP, no significant increases in antimicrobial resistance were observed over time, except for the penicillinase-labile penicillins (penicillin and ampicillin) among MSSP. However, in recent years, a few studies have reported higher-level of resistance to amikacin, gentamicin and enrofloxacin amongst MSSP. The review highlights inconsistencies between studies as a result of several factors, for example the use of different antimicrobial susceptibility testing methods and interpretation criteria. We recommend that data on susceptibility in important companion animal pathogens are collected and presented in a more harmonized way to allow more precise comparison of susceptibility patterns between studies. One way to accomplish this would be through systematic surveillance either at the country-level or at a larger scale across countries e.g. EU level.


      PubDate: 2014-06-10T14:37:23Z
       
  • Resistance to selected beta-lactam antibiotics
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): K. Nedbalcova , K. Nechvatalova , L. Pokludova , J. Bures , Z. Kucerova , L. Koutecka , A. Hera
      Susceptibility in vitro and trends in resistance to antimicrobials were determined by a dilution micromethod in a group of Actinobacillus pleuropneumoniae, Pasteurella multocida, Mannheimia haemolytica and Escherichia coli isolates from clinical cases of cattle and swine diseases in the Czech Republic from 2007 to 2011. A high susceptibility of pig and cattle respiratory pathogens to antimicrobials was found, with the exception of the moderate prevalence of M. haemolytica resistance to ampicillin. In contrast to respiratory pathogens, low susceptibility of E. coli of pig and cattle isolates to ampicillin and amoxicillin/clavulanic acid was noted. Regarding resistance trends, an increase in levels of resistance among E. coli isolates to ampicillin and amoxicillin/clavulanic acid was identified, but the resistance of respiratory isolates was low, with the exception of M. haemolytica. For the period of 2007–2011, there was a significant and almost continuous increase in sales (compared with population correction unit) of ceftiofur, cefquinome and other beta lactams for pigs. Consumption peaked in 2010. In the case of amoxicillin in combination with clavulanic acid, data showed a significant decrease in sales from 2007 to 2008, followed by a period of fluctuation. In cattle, within the groups of 3rd and 4th generation cephalosporins and for the whole group of other betalactams for the period of 2007–2011, there was a significant and almost continuous increase in sales (compared with population correction unit). Consumption peaked in 2010. In the case of ceftiofur, there was a huge increase noted from 2010. In the case of amoxicillin in combination with betalactamase inhibitor (clavulanic acid) data shows a significant decrease from 2007 to 2008, followed by a period of fluctuation in sales.


      PubDate: 2014-06-10T14:37:23Z
       
  • Emergence of AmpC-producing Escherichia coli in the broiler production
           chain in a country with a low antimicrobial usage profile
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Solveig Sølverød Mo , Madelaine Norström , Jannice Schau Slettemeås , Atle Løvland , Anne Margrete Urdahl , Marianne Sunde
      The aim of this study was to estimate the prevalence of cephalosporin-resistant Escherichia coli at the different levels of the Norwegian broiler production pyramid and identify the mechanisms responsible for the resistance phenotype. Samples from all levels of the broiler production pyramid and retail chicken meat (fillets) were included (n =649). The occurrence of cephalosporin-resistant E. coli at the different production levels ranged from 8 to 43%. All these isolates had an AmpC-phenotype, and the majority carried the bla CMY-2 gene. In addition, a few isolates with up-regulated chromosomal ampC were identified. The results show that Norway has a relatively high prevalence of cephalosporin-resistant E. coli in the broiler production chain in spite of a very low consumption of antimicrobial agents. Cephalosporins have not been used in the Norwegian broiler production, and it has been hypothesised that import of breeding animals and hatching eggs may be the source of these resistant bacteria. We demonstrate that these bacteria are disseminated in the production pyramid despite the lack of selection pressure from antimicrobial agents.


      PubDate: 2014-06-10T14:37:23Z
       
  • Comparative prevalence and characterization of ESBL-producing
           Enterobacteriaceae in dominant versus subdominant enteric flora in veal
           calves at slaughterhouse, France
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Marisa Haenni , Pierre Châtre , Véronique Métayer , Maxime Bour , Elodie Signol , Jean-Yves Madec , Emilie Gay
      Food-producing animals have become a growing reservoir of Extended-Spectrum Beta-Lactamase (ESBL)-producing bacteria. In cattle, veal calves are exposed to high amounts of antibiotics but ESBL prevalence data are still limited compared to other food sectors such as poultry production. Based on the investigation of 491 veal calves from different slaughtering batches at 12 abattoirs, this study shows a prevalence of 29.4% of ESBL producers in the faecal flora of veal calves in France in 2012. A variety of bla CTX-M genes was found, reflecting possible diverse pathways of dissemination in cattle. Another major conclusion is the comparison of the ESBL prevalence in the dominant versus sub-dominant Escherichia coli population of the same calves (1% and 29.4%, respectively). Also, the ESBL E. coli clones in the sub-dominant flora mostly differed from the non-ESBL dominant E. coli clones of the same calves. Of note, the distribution of bla CTX-M genes and E. coli phylogroups were similar to the ones previously found in ESBL E. coli clones from diseased calves. The hypothesis that ESBL genes may distribute more abundantly in certain backgrounds of E. coli was also discussed. In all, as recently reported in the Netherlands, these results strongly suggest a recent increase in the prevalence of ESBL carriage in French veal calves, which should be considered one of the major ESBL reservoirs in food animals.


      PubDate: 2014-06-10T14:37:23Z
       
  • Prevalence and characterisation of quinolone resistance mechanisms in
           Salmonella spp.
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4
      Author(s): Dariusz Wasyl , Andrzej Hoszowski , Magdalena Zając
      The study was focused on characterisation of quinolone resistance mechanisms in Salmonella isolated from animals, food, and feed between 2008 and 2011. Testing of Minimal Inhibitory Concentrations revealed 6.4% of 2680 isolates conferring ciprofloxacin resistance. Simultaneously 37.7% and 40.8% were accounted for, respectively, nalidixic acid and ciprofloxacin Non Wild-Type populations. Amplification and sequencing of quinolone resistance determining region of topoisomerases genes in 44 isolates identified multiple amino-acid substitutions in gyrA at positions Ser83 (N =22; →Leu, →Phe, →Tyr), Asp87 (N =22; →Asn, →Gly, →Tyr) and parC (Thr57Ser, N =23; Ala141Ser, N =1). No relevant mutations were identified in gyrB and parE. Twelve patterns combining one or two substitutions were related to neither serovar nor ciprofloxacin MIC. In 92 isolates suspected for plasmid mediated quinolone resistance two qnr alleles were found: qnrS1 (or qnrS3; N =50) and qnrB19 (or qnrB10; N =24). Additionally, two isolates with chromosomally encoded mechanisms carried qnrS1 and qnrS2. All tested isolates were negative for qnrA, qnrC, qnrD, qepA, aac(6′)-Ib-cr. Both chromosomal and plasmid mediated quinolone resistance determinants were found in several Salmonella serovars and Pulsed Field Gel Electrophoresis was used to assess phylogenetic similarity of selected isolates (N =82). Salmonella Newport was found to accumulate quinolone resistance determinants and the serovar was spreading clonally with either variable gyrA mutations, qnrS1/S3, or qnrB10/B19. Alternatively, various determinants are dispersed among related S. Enteritidis isolates. Antimicrobial selection pressure, multiple resistance determinants and scenarios for their acquisition and spread make extremely difficult to combat quinolone resistance.


      PubDate: 2014-06-10T14:37:23Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 16 July 2014
      Source:Veterinary Microbiology, Volume 171, Issues 3–4




      PubDate: 2014-06-10T14:37:23Z
       
  • Enterotoxigenic Escherichia coli infection induces intestinal epithelial
           cell autophagy
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Yulong Tang , Fengna Li , Bie Tan , Gang Liu , Xiangfeng Kong , Philip R. Hardwidge , Yulong Yin
      The morbidity and mortality in piglets caused by enterotoxigenic Escherichia coli (ETEC) results in large economic losses to the swine industry, but the precise pathogenesis of ETEC-associated diseases remains unknown. Intestinal epithelial cell autophagy serves as a host defense against pathogens. We found that ETEC induced autophagy, as measured by both the increased punctae distribution of GFP-LC3 and the enhanced conversion of LC3-I to LC3-II. Inhibiting autophagy resulted in decreased survival of IPEC-1 cells infected with ETEC. ETEC triggered autophagy in IPEC-1 cells through a pathway involving the mammalian target of rapamycin (mTOR), the extracellular signal-regulated kinases 1/2 (ERK1/2), and the AMP-activated protein kinase (AMPK).


      PubDate: 2014-05-12T06:18:39Z
       
  • HU-induced polymorphous filamentation in fish pathogen Edwardsiella tarda
           leading to reduced invasion and virulence in zebrafish
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Limei Wang , Jingfan Xiao , Shilei Cui , Qiyao Wang , Haizhen Wu , Qin Liu , Yuanxing Zhang
      Edwardsiella tarda is a rod-shaped Gram-negative pathogenic bacterium that causes hemorrhagic septicemia in fish. Nucleoid-associated protein HU is a basic DNA-binding protein with structural specificity in regulating genes expression. In wild-type E. tarda EIB202, HU is composed of two subunits HUα (hupA) and HUβ (hupB), and exists in homodimer or heterodimer forms. Different from the wild-type and ΔhupB mutant, ΔhupA mutant was found to be defective in cell growth, H2S production, acid adaptation, and exhibited abnormal cell division resulting in a filamentous phenotype in log phase bacteria. The qRT-PCR result showed that deletion of hupA significantly up-regulated the transcription levels of recA and sulA, which in turn stimulated RecA-dependent pathway to prevent cell division, resulting in filamentous morphology in E. tarda. Furthermore, the elongated ΔhupA cells showed a striking defect in EPC cell invasion, and the adhesion and internalization rates were reduced to 25% and 27% of the wild-type in log phase cultures. Confocal laser scanning microscopy revealed that filamentous bacteria failed to adhere to and could not be internalized into EPC. When some of the bacteria regained the rod-shape morphology in stationary cultures, the ΔhupA mutants showed increased adhesion and internalization rates into EPC. Moreover, ΔhupA mutant exhibited delayed mortalities (for two days) in zebrafish but the LD50 increased 17 folds. Immunohistochemical analysis showed that ΔhupA mutant reduced proliferation abilities in the muscle, liver and intestine of zebrafish. This study indicates that HU protein and strains morphology play essential roles in the virulence network of E. tarda.


      PubDate: 2014-05-12T06:18:39Z
       
  • Distribution of Capnocytophaga canimorsus in dogs and cats with genetic
           characterization of isolates
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Kaoru Umeda , Risa Hatakeyama , Takuto Abe , Koh-Ichi Takakura , Takayuki Wada , Jun Ogasawara , Shu-Ichi Sanada , Atsushi Hase
      Capnocytophaga canimorsus, which is often found in the oral cavities of dogs and cats, is sometimes transmitted to humans, causing severe infection. To elucidate the risk of C. canimorsus in humans and animals, this study was undertaken to characterize this bacterium epidemiologically and genetically. We examined the distribution of C. canimorsus in dogs and cats, and analyzed the correlation between the presence of bacteria and individual factors statistically. We also compared C. canimorsus isolates genetically using 16S rRNA gene sequence analysis and pulsed-field gel electrophoresis (PFGE). C. canimorsus was detected in 76 of 109 dogs (69.7%) and 57 of 104 cats (54.8%). A relation between C. canimorsus presence and some individual factors was detected both in dogs and cats, but the predictive factors of carrying the bacterium differed between dogs and cats. 16S rRNA gene sequences from C. canimorsus isolates in this study were combined with previously published sequences to assess their intra-specific phylogeny. Results show that C. canimorsus is classifiable into two main groups (I and II) with differing γ-glutamyl aminopeptidase activity. Strains from human patients belonged unevenly to group I, possibility suggesting that group I can be transmitted to humans and group II is indigenous only to the oral cavities of dogs and cats. PFGE genotyping showed high discriminatory power, and the dendrogram accorded with genetic segregation between isolates of group I and II. Sma I-digest PFGE developed for this study is useful as a molecular typing method for additional epidemiological and phylogenetic studies of C. canimorsus.


      PubDate: 2014-05-12T06:18:39Z
       
  • Comparison of diagnostic potential of serological, molecular and cell
           culture methods for detection of Q fever in ruminants
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Krzysztof Niemczuk , Monika Szymańska-Czerwińska , Krzysztof Śmietanka , Łukasz Bocian
      Q fever is an infectious disease caused by Coxiella burnetii. Diagnosis of Q fever based on clinical symptoms is unattainable; thus, different laboratory techniques are used to detect the infection. The aim of the study was to compare the diagnostic potential of ELISA, CFT, conventional PCR, real-time PCR and cell culture. The tests were carried out on 2251 serum samples from ruminants. Moreover, 668 placentas, 1277 vaginal swabs and 306 specimens of the internal organs of aborted foetuses were examined by PCR and cell culture. Pearson's chi-square test was used to compare the results obtained by ELISA, CFT, PCR, real-time PCR and isolation in cell culture. The χ 2 test confirmed that in most cases the results obtained by means of the different methods were correlated with each other (P <0.05). The highest correlation coefficients (r =0.76–0.87) were observed in the case of real-time PCR and conventional PCR. ELISA and CFT were moderately correlated (r =0.43–0.45). When the comparison was made between the results of tests run on samples from swabs and aborted foetuses, the r values between ELISA and CFT were lower than those between ELISA and PCRs. A negligible, or weak to moderate relationship was mostly observed when the method of cell culture isolation was compared with all the other analytical techniques investigated. The use of a combination of different laboratory methods, preferably ELISA for serology and polymerase chain reactions for the agent detection, is suggested to achieve the correct diagnosis of Q fever.


      PubDate: 2014-05-12T06:18:39Z
       
  • Evaluation of the single cervical skin test and interferon gamma responses
           to detect Mycobacterium bovis infected cattle in a herd co-infected with
           Mycobacterium avium subsp. paratuberculosis
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Juan Seva , Jose M. Sanes , Guillermo Ramis , Alberto Mas , Juan J. Quereda , Bernardo Villarreal-Ramos , David Villar , Francisco J. Pallares
      This study reports the performance of the single intradermal tuberculin (SIT) test and the interferon-gamma (IFN-γ) assay for Mycobacterium bovis in a cattle herd with high prevalence of paratuberculosis (PTB). A total of 58/350 animals were selected for necropsy based on one or more of the following criteria: positive to SIT, IFN-γ, a breeding cow that seroconverted to PTB and showed signs compatible with a wasting disease. Infection status was determined by post mortem diagnostic tests that included histopathology examination, mycobacterial cultures and PCR identification for M. bovis and Mycobacterium avium subsp. paratuberculosis (MAP). In 7/58 animals primary tuberculosis (TB) lesions, affecting only the retropharyngeal and/or mediastinal lymph nodes, were found; 3/7 animals were found SIT positive. PTB was confirmed in 35/58 animals, of which 30 had seroconverted and 14 had typical clinical signs. 45/58 animals were IFN-γ+ using the most stringent criterion (cut-off point≥0.05); however, IFN-γ test was only positive in 33 animals when using a higher threshold (cut-off point≥0.1). Three animals co-infected also showed extensive TB and diffuse PTB lesions. These results show that the combined use of SIT and IFN-γ, as interpreted using official guidelines, detected all confirmed cases of TB. Individually, the sensitivity of the SIT was inadequate to diagnose TB-positive animals with an advanced stage of PTB. The large number of IFN-γ+ animals with no visible TB lesion could be due, in part, to some protection conferred by prior infection with MAP.


      PubDate: 2014-05-12T06:18:39Z
       
  • Identification of Treponema pedis as the predominant Treponema species in
           porcine skin ulcers by fluorescence in situ hybridization and
           high-throughput sequencing
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Frida Karlsson , Kirstine Klitgaard , Tim Kåre Jensen
      Skin lesions often seen in pig production are of great animal welfare concern. To study the potential role of Treponema bacteria in porcine skin ulcers, we investigated the presence and distribution of these organisms in decubital shoulder ulcers (n =51) and ear necroses (n =54) by fluorescence in situ hybridization (FISH) and high-throughput sequencing. In addition, two cases of facial ulcers and five cases of other skin ulcers were included in the study. Samples from all 112 skin lesions and intact skin from pigs without skin ulcers (n =14) were screened by FISH. Three different oligonucleotide probes targeting 16S rRNA were used, specific for domain bacterium, Treponema spp. and species T. pedis. Screening showed that two cases each of facial and other ulcers, 35 (69%) of shoulder ulcers and 32 (59%) of ear necroses were positive for Treponema spp. T. pedis was the unequivocally, predominant species typically constituting more than 90% of the treponemes in a lesion, assessed visually by microscopy. Altogether, T. pedis was demonstrated in 69 of the 71 Treponema spp. positive lesions. We conclude that Treponema spp. are frequently present and abundant in various skin ulcers of pigs. The results from this study point toward an important role of T. pedis as a secondary bacterial infection in porcine skin ulcers, especially in severe and chronic lesions.


      PubDate: 2014-05-12T06:18:39Z
       
  • Beta2 toxin is not involved in in vitro cell cytotoxicity caused by human
           and porcine cpb2-harbouring Clostridium perfringens
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Janneke G. Allaart , Alphons J.A.M. van Asten , Johannes C.M. Vernooij , Andrea Gröne
      Clostridium perfringens is a common cause of intestinal disease in animals and humans. Its pathogenicity is attributed to the toxins it can produce, including the beta2 toxin. The presence of cpb2, the gene encoding the beta2 toxin, has been associated with diarrhoea in neonatal piglets and humans. However, the exact role of the beta2 toxin in the development of diarrhoea is still unknown. In this study we investigated the level of cytotoxicity to porcine IPI-21 and human Caco-2 cell-lines caused by porcine and human cpb2-harbouring C. perfringens and the significance of the beta2 toxin for the induction of cell cytotoxicity. Supernatants of porcine cpb2-harbouring C. perfringens strains were cytotoxic to both cell lines. Cell cytotoxicity caused by supernatant of human cpb2-harbouring C. perfringens strains was variable among strains. However, removal of the beta2 toxin by anti-beta2 toxin antibodies or degradation of the beta2 toxin by trypsin did not reduce the cytotoxic effect of any of the supernatants. These data suggest that beta2 toxin does not play a role in the development of cell cytotoxicity in in vitro experiments. In vivo studies are necessary to definitely define the role of beta2 toxin in the development of cell cytotoxicity and subsequent diarrhoea.


      PubDate: 2014-05-12T06:18:39Z
       
  • Co-infection of Atlantic salmon (Salmo salar), by Moritella viscosa and
           Aliivibrio wodanis, development of disease and host colonization
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Christian Karlsen , Christin Vanberg , Helene Mikkelsen , Henning Sørum
      Two species of bacteria are repeatedly isolated from farmed fish with winter-ulcer disease. Moritella viscosa is the aetiological agent of the disease; the significance of Aliivibrio wodanis is uncertain but has not been related to the primary pathogenesis. A cell culture infection model showed that A. wodanis adhered to, but did not invade the fish cells. Exposure to culture supernatant of A. wodanis caused the fish cells to vacoulate, retract, round up and detach from the surface, and rearrange the actin filaments of the cytoskeleton. These observations suggest that the bacterium secretes toxins into the extracellular environment. Any pathologic effect of A. wodanis and the effect of co-culturing with M. viscosa was studied in Atlantic salmon (Salmo salar) bath challenged with; only M. viscosa or only A. wodanis or both bacteria together. Both M. viscosa and A. wodanis were re-isolated from external surfaces and internal organs from live and deceased co-infected fish. It is further hypothesized that A. wodanis colonization might influence the progression of a M. viscosa infection. This is to our knowledge the first study that reproduces field observations where both bacteria infect Atlantic salmon.


      PubDate: 2014-05-12T06:18:39Z
       
  • Feline fecal virome reveals novel and prevalent enteric viruses
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Terry Fei Fan Ng , João Rodrigo Mesquita , Maria São José Nascimento , Nikola O. Kondov , Walt Wong , Gábor Reuter , Nick J. Knowles , Everardo Vega , Mathew D. Esona , Xutao Deng , Jan Vinjé , Eric Delwart
      Humans keep more than 80 million cats worldwide, ensuring frequent exposure to their viruses. Despite such interactions the enteric virome of cats remains poorly understood. We analyzed a fecal sample from a single healthy cat from Portugal using viral metagenomics and detected five eukaryotic viral genomes. These viruses included a novel picornavirus (proposed genus “Sakobuvirus”) and bocavirus (feline bocavirus 2), a variant of feline astrovirus 2 and sequence fragments of a highly divergent feline rotavirus and picobirnavirus. Feline sakobuvirus A represents the prototype species of a proposed new genus in the Picornaviridae family, distantly related to human salivirus and kobuvirus. Feline astroviruses (mamastrovirus 2) are the closest known relatives of the classic human astroviruses (mamastrovirus 1), suggestive of past cross-species transmission. Presence of these viruses by PCR among Portuguese cats was detected in 13% (rotavirus), 7% (astrovirus), 6% (bocavirus), 4% (sakobuvirus), and 4% (picobirnavirus) of 55 feline fecal samples. Co-infections were frequent with 40% (4/10) of infected cats shedding more than one of these five viruses. Our study provides an initial description of the feline fecal virome indicating a high level of asymptomatic infections. Availability of the genome sequences of these viruses will facilitate future tropism and feline disease association studies.


      PubDate: 2014-05-12T06:18:39Z
       
  • Rabies-virus-glycoprotein-pseudotyped recombinant baculovirus vaccine
           confers complete protection against lethal rabies virus challenge in a
           mouse model
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Qunfeng Wu , Fulai Yu , Jinfang Xu , Yang Li , Huanchun Chen , Shaobo Xiao , Zhen F. Fu , Liurong Fang
      Rabies virus has been an ongoing threat to humans and animals. Here, we developed a new strategy to generate a rabies virus vaccine based on a pseudotyped baculovirus. The recombinant baculovirus (BV-RVG/RVG) was pseudotyped with the rabies virus glycoprotein (RVG) and also simultaneously expressed another RVG under the control of the immediate early CMV promoter. In vitro, this RVG-pseudotyped baculovirus vector induced syncytium formation in insect cells and displayed more efficient gene delivery into mammalian cells. Mice immunized with BV-RVG/RVG developed higher levels of virus-neutralizing antibodies, and conferred 100% protection against rabies viral challenge. These data indicate that the RVG-pseudotyped baculovirus BV-RVG/RVG can be used as an alternative strategy to develop a safe and efficacious vaccine against the rabies virus.


      PubDate: 2014-05-12T06:18:39Z
       
  • Molecular characterization of border disease virus strain Aveyron
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Stefan Vilcek , Valeria Leskova , Denise Meyer , Alexander Postel , Paul Becher
      For the pestivirus border disease virus (BDV) at least seven major genotypes have been described (BDV-1–BDV-7). So far, complete genomic sequences have been reported for four BDV genotypes (BDV-1–BDV-4). In this study we report the entire genomic sequence of the noncytopathogenic (ncp) BDV-5 reference strain Aveyron. The viral genome encompasses 12,284 nucleotides (nt) and contains one large open reading frame (11,700nt) flanked by a 370 nt long 5′-untranslated region (UTR) and a 214nt long 3′-UTR. The genome organization as well as the lengths of the viral polyprotein (3899 amino acids) and the 5′-UTR are very similar to the ones of other BDV strains, while the 3′-UTR of BDV Aveyron is considerably shorter when compared to other BDV strains. Comparative analysis of complete coding sequences revealed that BDV Aveyron shares nucleotide sequence identities of 76.9% to 79.0% with the other BDV strains, and less than 72% identity with other pestiviruses. In contrast to other BDV strains, a unique insertion of four amino acids (KAPD) of unknown origin is present in the C-terminal part of the viral autoprotease NS2 encoded by BDV Aveyron. Immunoblot analysis revealed that infection of cells with the ncp BDV strain Aveyron comprising this unique insertion in NS2 resulted in the expression of high amounts of NS3 and thereby showed that BDV Aveyron significantly differs from other ncp BDV strains in terms of NS2-3 processing and production of NS3.


      PubDate: 2014-05-12T06:18:39Z
       
  • Effects of virulent and attenuated transmissible gastroenteritis virus on
           the ability of porcine dendritic cells to sample and present antigen
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Shanshan Zhao , Qi Gao , Tao Qin , Yinyan Yin , Jian Lin , Qinghua Yu , Qian Yang
      Virulent transmissible gastroenteritis virus (TGEV) results in an acute, severe pathology and high mortality in piglets, while attenuated TGEV only causes moderate clinical reactions. Dendritic cells (DCs), through uptake and presentation of antigens to T cells, initiate distinct immune responses to different infections. In this study, an attenuated TGEV (STC3) and a virulent TGEV (SHXB) were used to determine whether porcine DCs play an important role in pathogenetic differences between these two TGEVs. Our results showed that immature and mature monocyte-derived dendritic cells (Mo-DCs) were susceptible to infection with SHXB and STC3. However, only SHXB inhibited Mo-DCs to activate T-cell proliferation by down-regulating the expression of cell–surface markers and the secretion of cytokines in vitro. In addition, after 48h of SHXB infection, there was the impairment in the ability of porcine intestinal DCs to sample the antigen, to migrate from the villi to the lamina propria and to activate T-cell proliferation in vivo. In contrast, these abilities of intestinal DCs were enhanced in STC3-infected piglets. In conclusion, our results show that SHXB significantly impaired the functions of Mo-DCs and intestinal DCs in vitro and in vivo, while STC3 had the opposite effect. These differences may underlie the pathogenesis of virulent and attenuated TGEV in piglets, and could help us to develop a better strategy to prevent virulent TGEV infection.


      PubDate: 2014-05-12T06:18:39Z
       
  • Identification of novel bovine group A rotavirus G15P[14] strain from
           epizootic diarrhea of adult cows by de novo sequencing using a
           next-generation sequencer
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Tsuneyuki Masuda , Makoto Nagai , Hiroshi Yamasato , Shinobu Tsuchiaka , Sachiko Okazaki , Yukie Katayama , Mami Oba , Naomi Nishiura , Yukiko Sassa , Tsutomu Omatsu , Tetsuya Furuya , Satoshi Koyama , Junsuke Shirai , Koki Taniguchi , Yoshiki Fujii , Reiko Todaka , Kazuhiko Katayama , Tetsuya Mizutani
      There are few reports describing diarrhea of adult cattle caused by group A rotaviruses. Here, we report the identification of a novel bovine group A rotavirus from diarrhea of adult cows. A group A rotavirus was detected from an epizootic outbreak of diarrhea in adult cows with a decrease in milk production in Japan in 2013. The comprehensive genomic analyses from fecal samples by viral metagenomics using a next-generation sequencer revealed that it had an unreported genotype combination G15P[14]. The genome constellation of this strain, namely, RVA/Cow-wt/JPN/Tottori-SG/2013/G15P[14] was G15-P[14]-I2-R2-C2-M2-A3-N2-T6-E2-H3 representing VP7-VP4-VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5, respectively. Each gene segment of Tottori-SG was most closely related to Japanese bovine group A rotaviruses suggesting that Tottori-SG might have derived from multiple reassortment events from group A rotavirus strains circulating among Japanese cattle. No other diarrhea pathogen of adult cattle was detected by routine diagnosis and metagenomics. Viral metagenomics, using a next-generation sequencer, is useful to characterize group A rotaviruses from fecal samples and offers unbiased comprehensive investigations of pathogen.


      PubDate: 2014-05-12T06:18:39Z
       
  • Viral replication kinetics and in vitro cytopathogenicity of parental and
           reassortant strains of bluetongue virus serotype 1, 6 and 8
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Peter Coetzee , Moritz Van Vuuren , Maria Stokstad , Mette Myrmel , René G.P. van Gennip , Piet A. van Rijn , Estelle. H. Venter
      Bluetongue virus (BTV), a segmented dsRNA virus, is the causative agent of bluetongue (BT), an economically important viral haemorrhagic disease of ruminants. Bluetongue virus can exchange its genome segments in mammalian or insect cells that have been co-infected with more than one strain of the virus. This process, may potentially give rise to the generation of novel reassortant strains that may differ from parental strains in regards to their phenotypic characteristics. To investigate the potential effects of reassortment on the virus’ phenotype, parental as well as reassortant strains of BTV serotype 1, 6, 8, that were derived from attenuated and wild type strains by reverse genetics, were studied in vitro for their virus replication kinetics and cytopathogenicity in mammalian (Vero) cell cultures. The results indicate that genetic reassortment can affect viral replication kinetics, the cytopathogenicity and extent/mechanism of cell death in infected cell cultures. In particular, some reassortants of non-virulent vaccine (BTV-1 and BTV-6) and virulent field origin (BTV-8) demonstrate more pronounced cytopathic effects compared to their parental strains. Some reassortant strains in addition replicated to high titres in vitro despite being composed of genome segments from slow and fast replicating parental strains. The latter result may have implications for the level of viraemia in the mammalian host and subsequent uptake and transmission of reassortant strains (and their genome segments) by Culicoides vectors. Increased rates of CPE induction could further suggest a higher virulence for reassortant strains in vivo. Overall, these findings raise questions in regards to the use of modified-live virus (MLV) vaccines and risk of reassortment in the field. To further address these questions, additional experimental infection studies using insects and/or animal models should be conducted, to determine whether these results have significant implications in vivo.


      PubDate: 2014-05-12T06:18:39Z
       
  • Differences in the susceptibility of Japanese indigenous and domesticated
           Eurasian common carp (Cyprinus carpio), identified by mitochondrial DNA
           typing, to cyprinid herpesvirus 3 (CyHV-3)
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Takafumi Ito , Jun Kurita , Kei Yuasa
      In 2004, a massive mortality of wild common carp (Cyprinus carpio) due to CyHV-3 infection occurred in Lake Biwa. Although common carp of two different mitochondrial types (Japanese indigenous and domesticated Eurasian) occur in the lake, the majority of the dead fish seemed to be the indigenous type. The apparent high mortality in the indigenous type implies a higher susceptibility of this type to CyHV-3. To test the hypothesis that the susceptibility of indigenous and Eurasian types differ, we performed experimental infections with CyHV-3 among 2 groups of the indigenous type, and for the Eurasian type 4 groups of domesticated common carp and 4 groups of koi carp. Fish were immersed in CyHV-3 isolate and kept at 24°C. Both groups of the indigenous type died more rapidly compared with the 8 groups of the Eurasian type. Cumulative mortality in both indigenous groups reached 95–100%, whereas the cumulative mortalities of domesticated common carp (30–95%) and koi carp (35–100%) were more varied. CyHV-3 genome in the organs of the indigenous type increased more rapidly after the viral exposure and reached higher peak levels than those of the domesticated strain. These findings revealed that susceptibility of the indigenous type of carp to CyHV-3 can be considered especially high.


      PubDate: 2014-05-12T06:18:39Z
       
  • Characterization of two newly emerged isolates of porcine reproductive and
           respiratory syndrome virus from Northeast China in 2013
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Chao-liang Leng , Zhi-jun Tian , Wu-chao Zhang , Hong-liang Zhang , Hong-yue Zhai , Tong-qing An , Jin-mei Peng , Chao Ye , Long Sun , Qian Wang , Yan Sun , Lin Li , Hong-yuan Zhao , Dan Chang , Xue-hui Cai , Gui-hong Zhang , Guang-zhi Tong
      A newly emerged porcine reproductive and respiratory syndrome virus (PRRSV) that has caused severe reproductive losses in sows appeared in some regions of China in 2013. To explore the biology of this new PRRSV and understand more fully genetic diversity in PRRSV isolates from China, the complete genome of the two 2013 Chinese isolates, designated HLJA1 and HLJB1, were analyzed. Genomic sequence analysis showed that HLJA1 and HLJB1 shared 88.6–98.3% nucleotide identity with genotype 2 (North American type, NA-type) isolates, but only 61.1% with the genotype 1 (European type, EU-type) isolate of Lelystad virus, indicating that both these isolates belong to the NA-type PRRSV genotype. Phylogenetic analysis showed that the NA-type PRRSV isolates formed three subgroups (1, 2 and 3); representatives of these subgroups are VR-2332, CH-1a and HUN4, respectively. HLJA1 and HLJB1 belong to subgroup 2. Analysis of NSP2 revealed that HLJA1 has a 48-amino acid deletion at positions 473–480 and 482–521, unlike other HP-PRRSV isolates, while HLJB1 has only a 1-amino acid deletion at position 481 compared with CH-1a. Interestingly, HLJA1 replicated in PAM cells but not in MARC-145 cells, whereas HLJB1 replicated in both cell types. The neutralizing antibody titer of pig hyperimmune sera against HUN4 was significantly higher than that of HLJA1 or HLJB1. Additionally, genetic variability in GP5 and GP3 proteins and in the novel ORF5a protein was evident. In addition to elucidating the genetic relationships between PRRSV isolates, our results suggest that Chinese PRRSV will remain a pandemic virus.


      PubDate: 2014-05-12T06:18:39Z
       
  • The antigenic drift molecular basis of the H5N1 influenza viruses in a
           novel branch of clade 2.3.4
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Lei Zhong , Qingqing Zhao , Kunkun Zhao , Xiaoquan Wang , Guo Zhao , Qunhui Li , Min Gu , Daxin Peng , Xiufan Liu
      H5N1 subtype influenza A virus has evolved into many HA clades since late 1990s. Six circulating H5N1 influenza viruses clustered to a novel branch in clade 2.3.4 and could escape vaccine protection, indicating their antigenic drift. Eleven amino acids substitutions in three antigenic sites of the hemagglutinin of these isolates were found when compared with the hemagglutinin of the primary viruses in clade 2.3.4. On the backbone of the novel isolates A/chicken/Northern China/k0602/2010, we generated a panel of recombinant viruses with HA mutations of restoring the primary vaccine strain Re-5's amino acid and homologous antisera to determine the role of these substitutions. The results of cross-HI assay, micro-neutralization assay and the antigen map of the mutated recombinant viruses showed that three substitutions in antigenic site B, especially D205K, are the major contributors to the antigenic drift of the novel branch of clade 2.3.4. Our study highlights the importance of surveillance of antigenic drift of H5N1 viruses for the control and preparedness of pandemic threats.


      PubDate: 2014-05-12T06:18:39Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2




      PubDate: 2014-05-12T06:18:39Z
       
  • Pathogen bacteria adhesion to skin mucus of fishes
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Said Benhamed , Francisco A. Guardiola , Mohammed Mars , María Ángeles Esteban
      Fish are always in intimate contact with their environment; therefore they are permanently exposed to very vary external hazards (e.g. aerobic and anaerobic bacteria, viruses, parasites, pollutants). To fight off pathogenic microorganisms, the epidermis and its secretion, the mucus acts as a barrier between the fish and the environment. Fish are surrounded by a continuous layer of mucus which is the first physical, chemical and biological barrier from infection and the first site of interaction between fish's skin cells and pathogens. The mucus composition is very complex and includes numerous antibacterial factors secreted by fish's skin cells, such as immunoglobulins, agglutinins, lectins, lysins and lysozymes. These factors have a very important role to discriminate between pathogenic and commensal microorganisms and to protect fish from invading pathogens. Furthermore, the skin mucus represents an important portal of entry of pathogens since it induces the development of biofilms, and represents a favorable microenvironment for bacteria, the main disease agents for fish. The purpose of this review is to summarize the current knowledge of the interaction between bacteria and fish skin mucus, the adhesion mechanisms of pathogens and the major factors influencing pathogen adhesion to mucus. The better knowledge of the interaction between fish and their environment could inspire other new perspectives to study as well as to exploit the mucus properties for different purposes.


      PubDate: 2014-05-12T06:18:39Z
       
  • DNA vaccination with VP2 gene fragment confers protection against
           Infectious Bursal Disease Virus in Chickens
    • Abstract: Publication date: 25 June 2014
      Source:Veterinary Microbiology, Volume 171, Issues 1–2
      Author(s): Satya Narayan Pradhan , Prabhu Rajaiah Prince , Jayaprakasam Madhumathi , Chakkaravarthy Arunkumar , Parimal Roy , Rangarajan Badri Narayanan , Usha Antony
      Infectious Bursal Disease Virus (IBDV) causes immunosuppression in young chickens by destruction of antibody producing B cells in the Bursa of Fabricius and poses a potential threat to the poultry industry. We have examined the protective efficacy of a subunit DNA vaccine against IBDV infection in chickens in this study. An immunodominant VP2 gene fragment (VP252–417) was cloned into CMV promoter based DNA vaccine vector pVAX1 and in vitro expression of the DNA encoded antigens was confirmed by transfection of CHO cells with vaccine constructs followed by RT-PCR and western blot analysis using IBDV-antiserum. Two weeks old chickens were immunized intramuscularly with pVAXVP252–417 and the in vivo transcription of the plasmid DNA was confirmed by RT-PCR analysis of DNA injected muscle tissue at different intervals of post immunization. Tissue distribution analysis revealed that the plasmid DNA was extensively distributed in muscle, spleen, kidney, liver, and bursa tissues. Chickens immunized with pVAXVP252–417 developed high titer (1:12,000) of anti-VP252–417 antibodies. Further, chicken splenocytes from pVAXVP252–417 immunized group showed a significantly high proliferation to the whole viral and recombinant antigen (P <0.01) compared to control groups, which implies that pVAXVP252–417 codes for immunogenic fragment which has epitopes capable of eliciting both B and T cell responses. This is evident by the fact that, pVAXVP252–417 immunized chicken conferred 75% protection against virulent IBDV (vIBDV) challenge compared to the control group. Thus, the present study confirms that the immunodominant VP2 fragment can be used as a potential DNA vaccine against IBDV infection in chickens.


      PubDate: 2014-05-12T06:18:39Z
       
 
 
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